5m+12x=0.5+x
11x=0.5-5m
x=(0.5-5m)/11
x(m+1)=m(1+x)
x(m+1)=m+mx
x=m
所以
(0.5-5m)/11-m=2
0.5-5m-11m=22
16m=-21.5
m=-43/32